Electrical protective apparatus.



F. R. PARKER.

ELECTRICAL PROTECTIVE APPARATUS.

APPLICRTION HLEIJ MAY 29. I914.

WITNESSES: \x

UNITED STATES PATENT OFFICE.

FREDERICK R. PARKER, or CHICAGO, ILLINOIS.

ELECTRICAL PROTECTIVE APPARATUS.

Patented Oct. 30, 191 '7.

Original application filed August 20, 1904, Serial No. 221,519. Divided and this application filed May 29,

. I 1914. Serial No. 841,728.

I '0 all whom it may concern:

Be it known that I, FREDERICK R. PARKER, a citizen-of the United States of America, residing at Chicago, in the county of Cook and State of Illinois, have invented new and useful Electrical Protective Apparatus, of which the following is a specification, reference being had to the accompanying drawings, illustrating one form of my invention.

My invention relates to apparatus for protecting electrical circuits and apparatus from injurious electricity of various forms, this application being a division of my copending application Serial No. 221,519, filed August 20, 1904. v

.The principal object of this. present invention is to provide improved and-simplified electrical protective apparatus as and of the, character herein set forth.- Otherobjects will be apparent from the following specification.

In protective apparatus for electrical circuits and apparatus, such,-for example, as the apparatus of telephonesystems, or other circuits or systems, it is the usual practice to employ high-potential electricity arresters to protect the said circuits and apparatus from high-voltage currents or charges of electricity, such as lightning, and electrothermal devices to protect the said cir cuits and apparatus from sneak currents, that is, from currents of electricity. slightly in excess of the normal, whichcurrents in time, may burn out certain, parts of the ap-' paratus, due to a gradual heating. Heretofore there has been employed a certain class of devices for the high-potential electricity arresters and a distinctly difierent and separate class of devices for the electrothermal protectors. i

In my present invention I combine both of the above-mentioned classes of devices and thereby produce a single device which embodies both a high-potential electricity arrester and an electrothermal device, and which serves all of the purposes of both. Thus I provide a single device which has a small number of parts, to take theplace of the two distinctly different devices, and which, on account of its simplicity, may be very cheaply manufactured and very economically, efliciently and effectively utilized.

The advantages of my single device over the two distinctly different devices generally used, are very apparent and will be readily seen from the following detailed description which refers to the accompanying drawings illustrating one form of my invention.

In this invention I also provide an improved and simplified electrothermal protector which is very certain in its operation. I also provide means whereby abnormal electrical conditions in the higlrpotential electricity arrester may cause the operation of electrothermal mechanism to automatically disrupt a circuit leading to the ar roster, and also connect a portion of this circuit to earth if desired. Either one or both of these purposes may be accomplished, as desired, or the arrester may be adapted to control or switch various circuits upon abnormal electrical conditions therein. It will be readily seen that this feature in a highpotential electricity arrester is very advantageous.

,In the accompanying drawings illustrating one form of my invention, Figure 1 is a side elevation of a series of the devices of the invention mounted on a suitable supporting plate; Fig. 2 is a cross-sectional viewof the apparatus of the invention, taken on line as w of Fig. 1, with portions shown in elevation, showing the protective devices mounted on opposite sides of the supporting or mounting plate; and Fig. 3 is a perspective view of a portion of spring member 7 of the apparatus of Figs. 1 and. 2, showing the detailed construction thereof. Like characters refer to like parts in the several figures.

By reference to the drawings it will be seen that the mounting plate for the protective apparatus is preferably composed of two sheet-metal strips d (Z preferably formed as shown and secured together along one edge 0 preferably by suitable rivets 'n. n, the rearward portions of the strips or plates d (1 being spaced apart over the body thereof and held in such position by a suitable distance piece m. This mounting plate d d is preferably grounded and is preferably of such a length that a number of protective devices may be mounted on each side thereof as desired. It is not essential to form the mounting plate or ground plate;

d d as described, as various plates or J-supports, such as a part of the iron work of a distributing board, a protector rack, a cable head, etc, may be used for'this purpose."

As the apparatus mounted on opposite sides of the mounting plated d is in duplicate sets, Twill describe in. detail the apparatus on one side only ofthis plate d d, as

follows :e, f and g, are spring members which are mounted preferably fiatwise on the mounting plate (5 d by means of bolts is and Z, these spring members being suitably insulated from each other and'from the mounting plate d Z by suitable insulating bushings and washers m. The protector -'de-' vice proper, comprises conducting members placed between the rivets or pins n n which hold the device against lateral displacement. The conducting members a and b are prefer ably made of carbon or graphite, but may be made of other suitable materials, the member a being of sufiicient resistance to produce heat for operating the device upon the passage therethrough of a'n'abnormally large current. I Spring 0 ispreferablypro vided with a narrow portion'e at its fre'e' end adapt ed to'fit into a groove a f int the member a, to hold the-latter against lateral displacement. It will be seen that spr ng 0 does not-bear against the member a along.

substantially its entire length, as is usual-in ordinary lightning arr-esters, but merely e'ngages the member a near one end thereof so as to provide a conductive circuit through the body of a for nearly its entire length. This arrangement is provided for giving the proper heating effect in the thermal element a. A heatsusceptible pin h of conducting material, preferably of a low-melting-point solder, is inserted into a hole in one end of the block or member a so as to be firmly held in place thereby. The spring 1 is provided with a forked portion at its free end, preferably bent at right-angles to the body portion of the spring, adapted to firmly grasp the pin it as shown. The tension of springs e and f is toward the ground plate d d. Spring 9 is an alarm spring, and is provided when an alarm circuit for the protective apparatus is required. In a telephone system the line conductors are preferably connected to terminals 3 and 4: which lead to springs f f respectively, the switchboard conductors are connected to terminals 1 and 2 which lead to springs 6 e respectively, and the alarm circuit conductors are connected to terminals 5 and G which lead to springs g g respectively.

The thermalvprotector circuit through the device is fromswitchboariiterminal 1 (or 2), through spring 6, heat producing memher a, pin h, and spring f to line terminal 3 (or "4). The lightning arrester circuit through the device is from line terminal 3 (or 4), through spring f, pin h, conducting member a, dielectric p, conducting member I), and ground plate d d to ground. The alarm circuit is from terminal 5 (or- .6), through spring 9, and through a portion of the free end of spring 7 to the ground plate d (i when the thermal protector is operated. When a high-potential current or charge of electricity, such as lightning, comesto'the' protective apparatus overthe line spring f, it'passes through spring 7, pin h, conducting member-a, arcs through dielectric p to con ducting member 6', and then passes from I) through plate dd to ground,- the lightning arrester a p I) thus protecting the switch board circuit and apparatus connected with terminal 1 (or 2) from the high-voltage electricity.

lV-hen a current of electricity slightly in excess of the normal traverses the resistance member a for a short length of time, such current being of too low a voltage to are across the'dielectric p, or when a larger lowvoltage' current traverses the resistance mem her a, i't heats'the resistance members, and when'the'heat' issuflicient it softens or weakens the heat-susceptible pin h whereupon the spring f preferably pulls or shears "the'pin h a )art 'as shown 011 the'right of Fig. 2 and ma res contact withthe ground'plate d d asshowng This operation of spring f opens the circuitbetween the line and-switchboard springs f and 6, respectively, thus stopping the flow of'current through the heat-producing member a, and also grounds the line spring f. Thus it will be seen that the objectiona'ble current in spring 7'' is automatically switched from the switchboard spring e and the apparatus connected therewith, to ground, which protects the switchboard circuit and apparatus from the-harmful heat ing effect of the objectionable current. When spring 7 operates, it also engages spring 9 and thereby closes an'alarm circuit between spring '9 and ground plated (l.

' When a continued electric discharge passes through the lightning arrester a p b, the heat of the arc will also heat and soften the pin it and thereby allow spring 7 to pull or shear it apart and operate as above described. In thiscase the high-voltage current in spring f will be switched to ground by the spring 7 engaging the ground plate d d, which stops the arc in the arrester and protects :the apparatus and switchboard circuit from the dangers of the high-voltage current. Such a high-voltage'current may colne'from a cross of the line leading to the spring f, with a high-voltage line."

In restoring the apparatus to operative condition after the operation of spring 7, the portion comprising the block a and pin it may be repaired or replaced by a similar new portion, and the spring 7 engaged with the pin it as originally.

The device of this invention is also provided with means for facilitating the testing of the different circuits therethrough. For this purpose the contact members of a testing plug may be inserted between the conducting member a and the portion e, of spring e,- on either or both sides of the ground strip 0, to open the respective contacts between springs e e and their conducting members a a and thereby allow the different circuits, such as the line and switch.- board circuits, to be tested.

I desire it to be understood that the conducting members or electrodes (1 and b, and especially the heat-producing member a, may be shaped and proportioned as desired, to fulfil the requirements.

Furthermore, I desire it to be understood that the heat for causing the operation of the thermally-operable device may be produced by various forms of electric currents, by a continued are through the arrester, or by a strong arc of short duration.

I do not wish to limit this present invention to the particular device herein shown, nor ,to the particular details of construction shown, as various modifications thereof may be made or utilized without departing from thesco'pe of the appendedclaims.

I further desire it to be understood that the device of this invention may be adapted for use on various circuits and in various systems, and also under various'conditions.

Certain features of the protector herein set forth form the subject-matter of my United States Letters Patent No. 1,238,728, dated Aug. 28, 1917, of which this present application is a division \Vhat I claim as my invention is:

l'. The combination with an electrical heating device having a heater of aggregated comminuted material, of a conducting member holding the heating device in place and making electrical connection therewith, a onepie'ce spring member, and heat-susceptible material making actual contact with the said spring member and connecting same with the heating device, the said spring member exerting a shearing stress on the said heat-susceptible material tending'to disrupt the said heat-susceptible connection.

2. The combination with electrothermal apparatus having a resistance heater device, of a conducting member holding the resistance heater device in place and electrirally connected therewith, a' one-piece conducting member, one of the said conducting members being a spring member, and heatsusceptible material normally connecting the second-mentioned 1 conducting member with the resistance-heater device and holding the said spring member under tension 'thesaid second-mentioned conducting member being in actual contact with the heatssusceptible material and exerting a shearing stresson the latter tending to disrupt the heatsusceptible connections I i '3; The combination with electrothermal apparatus having a heating device, of a conductingmember holding the heating device in place and electrically :connected therewith, a one-piece spring member, and heatsusceptible material normally connecting the said spring member with the heating device and holding said spring member under tension, the saidspring member being in actual contact with the heat-susceptible material and exerting'sishearing stress on= the latter tending to disrupt the heat-susceptible connection: I w

4:. The combination with electricalzapnotectire apparatus; having a heating device, of acne-piece spring member, and heat-susceptible material normally connecting the said spring member withthe heating device, the said spring member being in actual contact with the heat susceptible' material and exerting a shearing stress on the latter tend ing to disruptthe said heat-susceptible connection." v

5. In automaticallyoperable protective apparatus having a suitable support and an excess-current resistance-heater '-device, a one-piece conducting member mounted to the said support, and heat-susceptible material normally connecting the said conducting member with the resistance heater' device, the saidconducting'member being irractual contact with the said heat-susceptible material 'a'nd'exerting a shearing stress onthe latter tending to disrupt the said heat-susceptibleconnection. i

6. The combination with electrical protective apparatus having a suitable support and a-lieating'device, of a spring member mounted'to thel'said'support and having the-free end thereof extending at substantially rightangles to the "body portion and integral therewith, and heat-susceptible'material'normally connecting the said free end. of} the spring member with the heating device,'the said free end of the spring member being forked and actually engaging the said heatsusceptible material and exerting a shearing stress on the latter tending to disrupt the said heat-susceptible connection.

"7. In automaticallyoperable protective apparatus having a suitable support and a heating device, a conducting member mount-' ed to thesaid support and having the free end thereof extending at substantially right-. angles to the body portion and integral therewith, and' heat-susceptible material normally connecting the said free end of the conducting member with the heating device, the said free end of the conducting member being forked and actually engaging the said heat-susceptible, material and exerting a shearing stress on the lattertending to disrupt the said heat-susceptible connection.

8. The combination with :electricalaprotective apparatus having a heating device, of a spring member-having a portion thereof extending at an angle with the body portion and integral therewith, and fusible me tallic-solder normally connecting the said angularly-extendi-ng :portion with theheating device, the said angularly extending portion beingin actual contact .With the said fusible metallicsolder and exerting .a shear-. ing stress on the latter tending to disrupt the fusible connection.

9. In automatically-operable protective apparatus having a suitable'su'pport and a resistance-heater device, a conducting member mounted to the said supportand-having a portion thereof extending at an angle with the body portion and-integral therewith, and fusible metallic substance normally con.- necting the saidv anguIarlyTeXtending vportion with the resistance-heater device, the said angularly-extending portion being-in actual contact with the said'fusible metallic substance and exerting a shearing stress on the latter tending to disrupt the fusibleconnection. a a

10. The combination with automaticallyoper-able electrothermalapparatus having a heating device, ofia spring member having a portion thereof extending at an angle with the body portion and integral.- therewith, and heat-susceptible.material normally conmeeting .the said angularly-extending portion with the heatin device, the said-angularlyextending portion being in actual con tact with the said heat-susceptible material and exerting a shearing stress on the latter.

,11. In automatically-operable electrothermal apparatus having a suitable support and a resistanceheater device, a conducting member mounted to thesaid support and having a portionvthereof extending at an anglewith the body portion and integral therewith, and ,heatsusceptible material normally connecting the said angularly-ex tending portion with the resistanceheater device, the said angularly-extendmg portion being in actual vcontact with the said heatsusceptible material and exertmg. a shearing stress on the latter.

12. The combination with an electrothermal device having a heating element of aggregated comminuted material, of a spring member in direct contact with the heating element and holding same in place, a onepiece spring member, and heat-susceptible material making actual contact with the secondementioned spring member and holding vsame in. electrical iconnectionwith the heating element, -at leastr-one of the said spring members ,being adapted -to control the circuit of the saidqdevice when released. 13. The combination with an electrothermal device having a suitable ,supp ortj -and a heating element of aggregated comminuted material, of a conducting member mounted totthesaidsupport,- in direct contact with the'heating element and holding same in, place, a one-piece conducting-merry bermounted to the said support, and heat susceptible. material rma kin gaactua'l contact with the said one-piece conducting member and holdingsame in electrical ,connection with ,the;heating =element, one ,of the said conducting members. being. a spring memberadapted to cont1'ol ,the circuit of the said device when ;=released. v V

14. The icomhination with an. electrothermal device havingia suitable support and a heating element, of aconducting member mounted to the said sup'port, -in direct contact with; the heating element, and holding same place, a one-piece conducting member mounted. to thegsaid support, and heatsusceptible material making actual contact with, the said one piece conducting member and holding samein electrical connection with the heating-element, one ofthe said conducting members: being a spring member adapted-to, control-the ,circuit of the said.

device when released;

= 15. In 'electricalvprotective apparatus having a suitablesupport therefor and a heating device, a one piece spring member mounted to the said support, and fusible metallic solder normally connecting the said spring memberwith the heating device, the said spring member-being in actual contact with the metallic :solder and exerting a shearing stress thereon. I

i 16. In eledtrical protectiveapparatus having a suitable support therefor and a heating device, a one-piece conducting member mounted to the said support and having a ,forked end portion, and heat-susceptible material normally connecting the said conducting member with-the heating device, the said forkedend portion of the said conducting member actually engaging the said heat-susceptible material and exerting a shearing stress thereon.

17. In electrical protective apparatus having a suitable support therefor and a heating device, a one -piece spring member mounted to the said, support and having a forked end portion, and fusible metallic solder normally connecting the said spring member with the heating device, the said forked end portion of the said spring member actually engaging the said fusible metallie solder and exerting a shearing stress thereon.

18, In electrical protective eppamtushevfusible metallic solder and exerting eshearing it suitable support therefor and a heating stress thereon. ing device, :1 onepiece spring member As inventor of the foregoing I hereunto mounted to the said support and having a subscribe my name this 26th day of May, 5 forked end portion extending at substan- 1.914.

tiall right-angles to the body portion, and 1 r 1 fusil ile metallic solder normally connecting FREDERICK PARKER the said spring member with the heating de- Vitnesses: vice, the said forked end portion of the said tAYMoNn WIGKHAM,

10 spring member actually engaging the said THEODORE KIRGHEL.

Copies of this patent may be obtained for five cents each, by addressing the Gommlssioner of Patents, Washington. D. (1. 

